International Atomic Energy experts have located "unexplained" plutonium and highly enriched uranium traces in a nuclear waste facility in Iran and ha

International Atomic Energy experts have located "unexplained" plutonium and highly enriched uranium traces in a nuclear waste facility in Iran and have asked Tehran for an explanation, an IAEA report said Tuesday.

The report, according to the AP, also faulted Tehran for not cooperating with the agency's efforts to investigate suspicious aspects of Iran's nuclear works that have lead to fears it might be interested in developing nuclear weapons. And it said it could not confirm Iranian claims that its nuclear activities were exclusively nonmilitary unless Tehran increased its openness.

"The agency will remain unable to make further progress in its efforts to verify the absence of undeclared nuclear material and activities in Iran," without additional cooperation by Tehran, said the report, by IAEA chief Mohamed ElBaradei.

Such cooperation is a "prerequisite for the agency to be able to confirm the peaceful nature of Iran's nuclear program," it added.

The U.S. and some of its allies allege that Iran is developing nuclear arms and are suspicious of its intentions.